It is known that by various processes household, trade and also industrial refuse or waste can be sorted into several fractions and worked up into usable crude or raw materials.
According to each of the German Pat. No. 31 05 597 and the German Patent Application Nos. P 36 14 324.3 and P 36 14 325.1 of the applicant, the waste is divided into three main fractions, such as
ferrous metals PA1 granulated dense materials (dense fraction) and PA1 light fraction (fibrous materials). PA1 In the case of composting, since the plastics material mainly present does not rot. PA1 In the case of burning, as plastics material releases heavy metals and chloride. PA1 In the case of the manufacture of compacts, which are manufactured under pressure, as, particularly when plastics material foils are present, the stability of the compacts is impaired. PA1 Because of the moistening with water the particles often cling (stick) tightly to one another, whereby separation is prevented. PA1 High water utilization. PA1 Dirty water results which has to be purified. PA1 Relatively high energy utilization.
The latter consists of organic, compostable or combustible constituents such as paper, wood, textiles, plants, etc., mixed with particles of plastics material, especially plastics material foils, that can be made air-borne.
On the one hand, plastics material is a material that interferes with subsequent treatment:
On the other hand plastics material is a material that can be added in subsequent treatment, especially when it is a thermoplastic such as polyethylene.
A separating process is already known in which plastics material and paper are separated by means of water, with which the mass to be separated is sprayed until the absorbent paper fibres or particles are saturated and exhibit a higher density than the plastics material particles, especially plastics material foils. Subsequently the particles are separated from one another in a wind channel. After separation the fractions have to be dried. This process has the following disadvantages:
It has also already become known to remove plastics material particles by hand, after optical examination, from waste which is supplied as a stream of material. This process is very time consuming as well as involving high labor costs, and becomes more difficult to carry out as the size of the plastics material particles decreases.